The literature is replete with designs relative to cross flow and tangential fans. Pertinent references are:
U.S. Pat. No. 1,548,341 to Elemer Banki teaches a water turbine with backward facing blades and a flap to control flow.
U.S. Pat. No. 1,838,169 and U.S. Pat. No. 1,823,579 to E. L. Anderson teach a heating and ventilation unit where the blower is offset within the duct.
U.S. Pat. No. 1,920,952 to E. L. Anderson teaches a line-flow fan in which there is a guide from the duct wall which is directed to a point of neutral pressure on the periphery of the fan.
U.S. Pat. No. 2,658,700 to A. R. Howell teaches a turbo compressor with multiple concentric sets of blades for use in aircraft.
U.S. Pat. No. 3,082,976 to Peter Dornier teaches a combination aerodynamic and ground effect flight craft including a fan for taking air from above the .backslash.wings and ejecting it below the wings.
U.S. Pat. No. 2,914,243 and RE 25,365 to Bruno Eck teach the use of a fan which is neither radial or axial flow but which utilizes guide vanes within the fan to reduce fan noise output.
U.S. Pat. No. 3,161,348 to Nikalous Laing teaches a cross flow fan where the air flow is across the center and complex ducting is used to control the air flow.
U.S. Pat. No. 3,460,647 to Nikalous Laing teaches a hovercraft in the form of an automobile. Cross flow, i.e., tangential blowers positioned on each side of the automobile provide the desired lift.
U.S. Pat. No. 3,481,530 to A. G. Korovkin teaches a diametral fan duct work with internal vanes to control air flow.
From the plethora of references available, it is obvious that blade, fan, and duct design selections vary with the design objectives. Thus, the references relate to many subjects, e.g., reducing exhaust noise, shifting exhaust noise to a desired frequency band and reducing the energy required to drive the fan.
Basically, it appears that there is data available relative to designing combinations of fans and ducting for items ranging from cooling microelectronic devices and air conditioners to powering hovercraft and aircraft. As a result, the teachings of some references are appropriate for their designated purposes while the same teachings will be of little relevance for other purposes.
The tangential fan/duct combination of this invention provides a high volume/high velocity exhaust gas which is substantially proportional to the much lower fan rpm, i.e., at ratios of exhaust gas velocity to blade tip speed of 2.5:1. Its uses range from tennis and baseball pitching machines to craft, which can combine hover and aerodynamic flight operations. This capability, for example, enables the pilot of the craft to follow the procedures utilized with aerodynamic flight aircraft while flying, i.e., for aerodynamic flight take off, the engine operation is at maximum power (rpm) while landing at reduced power (rpm).